Ceiling suspended shelf

ABSTRACT

An overhead transport vehicle temporarily places a FOUP at a ceiling suspended shelf while transporting the FOUP to a target position by traveling along a rail on a ceiling of a building from which the ceiling suspended is suspended. The ceiling suspended shelf includes an upper shelf including an upper support surface that supports the FOUP. A level of the upper support surface is the same or substantially the same as a level of the rail.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a ceiling suspended shelf where anoverhead transport vehicle temporarily places articles.

2. Description of the Related Art

Conventionally, an overhead transport vehicle for transporting articlesalong a rail disposed on a ceiling is used in, for example, a factoryfor manufacturing semiconductor products. The factory sometimes has ashelf where articles transported by the overhead transport vehicle aretemporarily stored. A transport system including the overhead transportvehicle and shelf as mentioned above is disclosed in Japanese PatentApplication Laid-Open No. 2017-30944.

The overhead transport vehicle according to Japanese Patent ApplicationLaid-Open No. 2017-30944 includes an elevator device for loweringarticles and a lateral transfer device for laterally moving articles.Japanese Patent Application Laid-Open No. 2017-30944 has a plurality ofshelves, which are supported by poles and are arranged one aboveanother. The overhead transport vehicle is capable of lowering articlesto a predetermined height of the shelf with the elevator device, andthen laterally moving the articles, to place the articles in the shelf.

In a factory for manufacturing semiconductor products like the one shownin Japanese Patent Application Laid-Open No. 2017-30944, as theprocessing speed of a processing apparatus increases, a capacity forstoring additional articles may be required. Not only factories formanufacturing semiconductor products but also various buildings whereoverhead transport vehicles are disposed may be required to have aconfiguration capable of storing additional articles, too.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide ceiling suspendedshelves that are each able to place articles at a position wherearticles could not be placed conventionally.

The problem to be solved by the preferred embodiments of the presentinvention is as stated above. In the following, solutions to the problemas well as advantageous effects thereof will be described.

A preferred embodiment of the present invention provides a ceilingsuspended shelf configured as follows. The ceiling suspended shelf,being suspended from the ceiling, is a shelf where an overhead transportvehicle temporarily places articles to be transported to a targetposition. The overhead transport vehicle travels along the railsuspended from the ceiling, and transports the articles. The ceilingsuspended shelf includes an upper shelf including an upper supportsurface that supports the articles. A level of the upper support surfaceis the same or substantially the same as a level of the rail.

Accordingly, the articles are able to be placed at a high position in aspace that has conventionally not been available to place articles, thusproviding more effective use of a space in the building.

In the ceiling suspended shelf, the upper shelf may include a switchingmechanism to switch the state of the upper shelf between an open statethat allows the articles to pass from below to above the upper shelf anda closed state that allows the upper shelf to support the articles anddoes not allow the articles to pass from below to above the upper shelf.

Accordingly, an operation to place the articles in the upper shelf,which locates the articles at a high position, is able to be implementedfrom below. Thus, the operation to place the articles is able to besimple.

In the ceiling suspended shelf, the switching mechanism may switchbetween the open state and the closed state in response to receiving anexternal driving force.

Accordingly, the cost of the ceiling suspended shelf is able to bereduced, as compared to a drive source being provided for each ceilingsuspended shelf.

The ceiling suspended shelf may be provided as follows. The upper shelfincludes a first shaft, a first support portion, a second shaft, and asecond support portion. The first shaft is able to rotate. The firstsupport portion rotates integrally with the first shaft. The secondshaft is able to rotate, and has its axial center different to that ofthe first shaft. The second support portion rotates integrally with thesecond shaft. The switching mechanism switches between the open stateand the closed state by transmitting to the first shaft an externaldriving force as a rotational force while transmitting to the secondshaft the external driving force as a rotational force in the directionreverse to the rotational force transmitted to the first shaft.

Accordingly, it is not necessary to independently drive the first shaftand the second shaft, which simplifies a drive system. If the firstshaft and the second shaft were rotated in the same direction, the firstsupport portion would be rotated upward while the second support portionwould be rotated downward, resulting in a larger space occupied in theup-down direction of the upper shelf at a time of the state switching.In this respect, rotating the first shaft and the second shaft indifferent directions causes the first support portion and the secondsupport portion to move up or down in the same direction, whichcontributes to a reduction of an occupied space in the up-downdirection.

The ceiling suspended shelf may be provided as follows. The switchingmechanism includes a coupling link mechanism that couples the firstshaft to the second shaft. The coupling link mechanism includes a firstcoupling link and a second coupling link. The first coupling link ispositioned on the side close to the first shaft. The second couplinglink is positioned on the side close to the second shaft, is coupled tothe first coupling link, and rotates in the direction reverse to arotation direction of the first coupling link.

Accordingly, by using the links, the first shaft and the second shaftare able to be rotated in different directions.

The ceiling suspended shelf may be provided as follows. The switchingmechanism includes a first shaft link, a second shaft link, and acoupling link. The first shaft link rotates integrally with the firstshaft. The second shaft link rotates integrally with the second shaft.The coupling link couples the first shaft link to the second shaft linkand the first shaft link and the second shaft link rotate in differentdirections.

Accordingly, by mainly using the single coupling link, the first shaftand the second shaft are able to be rotated in different directions,thus providing a simple mechanism.

The ceiling suspended shelf may be provided as follows. The switchingmechanism includes a first pulley, a first belt, a first gear, a secondgear, a second pulley, and a second belt. The first belt is wound aroundthe first pulley, and rotates the first shaft. The first gear rotatesintegrally with the first pulley in the same direction as the firstpulley. The second gear is meshed with the first gear directly or via aneven number of gears, to thereby be rotated in the direction reverse toa rotation direction of the first gear. The second pulley rotatesintegrally with the second gear in the same direction as the secondgear. The second belt is wound around the second pulley, and rotates thesecond shaft.

Accordingly, by using the belts and pulleys, the first shaft and thesecond shaft are able to be rotated in different directions.

The ceiling suspended shelf may be provided as follows. The switchingmechanism includes a coupling belt, a first reel, and a second reel. Thefirst reel rotates integrally with the first shaft, the first reelincluding the coupling belt wound thereon. The second reel rotatesintegrally with the second shaft, the second reel including the couplingbelt wound thereon in the same winding direction as on the first reel.As the first reel is rotated by an external driving force and thecoupling belt is wound onto the first reel, the second reel is rotatedin the direction reverse to a rotation direction of the first reel. Asthe second reel is rotated by an external driving force and the couplingbelt is wound onto the second reel, the first reel is rotated in thedirection reverse to a rotation direction of the second reel.

Therefore, the belt may not be looped. Accordingly, a short belt is ableto be used to rotate the first shaft and the second shaft in differentdirections.

The ceiling suspended shelf may be provided as follows. The ceilingsuspended shelf further includes a lower shelf in addition to the uppershelf, the lower shelf overlapping the upper shelf in a plan view. Thelower shelf is located lower than the upper shelf. The lower shelf doesnot allow the articles to pass therethrough in an up-down direction.

Since the shelves are able to be provided one above the other, the spacein the building is able to be used more effectively.

In the ceiling suspended shelf, the number of the articles that are ableto be placed in one compartment may be smaller in the upper shelf thanin the lower shelf.

Accordingly, articles are able to be placed efficiently based on, forexample, a difference in how each article is transported.

The ceiling suspended shelf may be provided as follows. The article is awafer transport container to transport wafers. The upper shelf includes,on the upper support surface, an insertion pin that is able to bereceived in a recess formed in a bottom surface of the wafer transportcontainer.

Accordingly, the presence of the insertion pin in the upper shelf isable to stabilize the posture of the wafer transport container.

The ceiling suspended shelf may be provided as follows. The targetposition is a position where the wafer transport container is placedtoward a processing apparatus to process the wafers. The upper shelf islocated at a position higher than the target position.

Accordingly, a space located higher than a load port is able to be usedeffectively.

In the ceiling suspended shelf, the upper shelf may include uppershelves that are located on opposite sides across the rail.

Accordingly, the space in the building is able to be used furthereffectively.

The ceiling suspended shelf may be provided as follows. The ceilingsuspended shelf includes an upper side surface guide that faces a sidesurface of the article supported by the upper shelf. The upper sidesurface guide is located at a position higher than the lower end of therail.

Accordingly, the upper shelf is able to be provided at a relatively highposition.

The ceiling suspended shelf may include, on a back side the ceilingsuspended shelf, an anti-drop structure that prevents the articles fromdropping, where the back side is the side opposite to a front sidefacing the rail.

Accordingly, dropping of the articles is able to be prevented morereliably when, for example, the articles are transferred to the ceilingsuspended shelf.

The above and other elements, features, steps, characteristics, andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing a transport system including a ceilingsuspended shelf according to a first preferred embodiment of the presentinvention.

FIG. 2 is a front view showing an overhead transport vehicle and ceilingsuspended shelves.

FIG. 3 is a perspective view showing the overhead transport vehicle andthe ceiling suspended shelf.

FIG. 4 is a block diagram showing a driver, and the like, providedmainly in the overhead transport vehicle.

FIG. 5 is a front view showing a lower shelf transfer device of theoverhead transport vehicle.

FIG. 6 is a perspective view showing a retraction mechanism provided onthe bottom surface side of a FOUP.

FIG. 7 is a perspective view illustrating an upper shelf being switchedfrom a closed state to an open state.

FIG. 8 is a perspective view illustrating a lateral slide mechanism andan upward slide mechanism of an upper shelf transfer device beingoperated.

FIG. 9 is a perspective view illustrating FOUPs being placed on theupper shelf.

FIG. 10 is a block diagram showing a driver, and the like, provided inan overhead transport vehicle according to a second preferred embodimentof the present invention.

FIG. 11 is a front view illustrating an upper shelf transfer device ofthe second preferred embodiment of the present invention being operated.

FIG. 12 is a front view showing a ceiling suspended shelf according to athird preferred embodiment of the present invention.

FIG. 13 is a perspective view showing an overhead transport vehicleaccording to any of fourth to seventh preferred embodiments of thepresent invention.

FIG. 14 is a perspective view showing an upper shelf according to any ofthe fourth to seventh preferred embodiments of the present invention.

FIG. 15 is a front view showing how the upper shelf of the fourthpreferred embodiment of the present invention switches from the closedstate to the open state.

FIG. 16 is a front view showing how the upper shelf of the fifthpreferred embodiment of the present invention switches from the closedstate to the open state.

FIG. 17 is a front view showing how the upper shelf of the sixthpreferred embodiment of the present invention switches from the closedstate to the open state.

FIG. 18 is a front view showing how the upper shelf of the seventhpreferred embodiment of the present invention switches from the closedstate to the open state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described withreference to the drawings. First, referring to FIG. 1, overview of atransport system 1 will be described. FIG. 1 is a plan view showing thetransport system 1 according to a first preferred embodiment of thepresent invention.

The transport system 1 of this preferred embodiment, which is installedin a factory (building, facility) to manufacture semiconductor products,is a system to transport various articles. Articles transported by thetransport system 1 of this preferred embodiment are FOUPs (Front-OpeningUnified Pods) in which wafers (semiconductor wafers) are contained. Thearticles may be reticle pods in which reticles are contained. As shownin FIG. 1, the transport system 1 includes a rail 2, an overheadtransport vehicle 3, and ceiling suspended shelves 6.

The rail 2 is provided on a ceiling 7 of the factory. The overheadtransport vehicle 3 is able to travel along the rail 2 while beingsuspended. Two or more overhead transport vehicles 3 may be provided,though only one overhead transport vehicle 3 is shown in FIG. 1.

In the factory, processing apparatuses 4 and load ports 5 are provided.The processing apparatus 4 is an apparatus that performs variousprocesses on wafers contained in a FOUP. The load port 5 is connected toa space where the processing apparatus 4 performs processes. A FOUPtransported by the overhead transport vehicle 3 is placed on the loadport 5. Wafers in the FOUP are taken out, and then are processed by theprocessing apparatus 4. After being processed, the wafers are broughtinto the FOUP. Then, the same or another overhead transport vehicle 3transports this FOUP to a position where another step is performed.Here, the load port 5 may be provided below the ceiling suspendedshelves 6 as shown in FIG. 1, or the load port 5 and a temporary storageshelf (not shown) may be provided below the rail 2.

The ceiling suspended shelves 6 are provided on the ceiling 7 of thefactory. The ceiling suspended shelves 6 are shelves where FOUPs, etc.are temporarily placed when, for example, the processing apparatus 4 andthe load port 5, which are target positions, are occupied (in use). TheFOUPs, etc. are temporarily placed there until the processing apparatus4 and the load port 5 become unoccupied (available). In this preferredembodiment, the ceiling suspended shelves 6 are provided in parallel tothe rail 2 and along the longitudinal direction of the rail 2. Althoughthe ceiling suspended shelves 6 of this preferred embodiment areprovided on both sides of the rail 2, a ceiling suspended shelf 6 may beprovided on one side only.

Next, referring to FIG. 2 to FIG. 6, a detailed description will beprovided to the rail 2, the overhead transport vehicle 3, and theceiling suspended shelves 6. In perspective views in FIG. 3, etc., theceiling suspended shelf 6 provided on one side of the rail 2 and ananti-drop structure 67 which will be described later are not shown.

As shown in FIG. 2, poles 8 are connected to the ceiling 7 of thefactory. By the poles 8, the rail 2 and the ceiling suspended shelves 6are suspended from the ceiling 7. The overhead transport vehicle 3 issuspended from the ceiling 7 via the poles 8 and the rail 2.

As shown in FIG. 2 and FIG. 3, the ceiling suspended shelf 6 includesside plates 61, an upper shelf (first shelf) 62, and a lower shelf(second shelf) 65. The side plates 61 are suspended from the ceiling 7by the poles 8. The side plates 61 support the upper shelf 62 and thelower shelf 65. The side plates 61 are provided at regular intervals. Aspace provided between two side plates 61 corresponds to onecompartment. The ceiling suspended shelf 6 includes two or morecompartments with identical or similar features that are continuouslyprovided.

According to the structure of the upper shelf 62, two FOUPs 80 are ableto be placed in one compartment. The upper shelf 62 is located at aposition higher than the lower shelf 65. An upper support surface 62 a(FIG. 2, the first support surface) of the upper shelf 62, whichsupports a FOUP 80, has substantially the same height as that of therail 2. To be specific, the level of the upper support surface 62 a islocated between a vicinity of the lower end of the rail 2 and a vicinityof the upper end of the rail 2. Here, the wording “substantially thesame” is used to encompass a case where the level of the upper supportsurface 62 a is slightly lower than the lower end of the rail 2 and acase where the level of the upper support surface 62 a is slightlyhigher than the upper end of the rail 2. The level at which the uppersupport surface 62 a supports a FOUP 80 is higher than the level atwhich the overhead transport vehicle 3 supports a FOUP 80 whiletraveling, and is higher than the level at which the load port 5supports a FOUP 80. The level of the upper support surface 62 a ishigher than the upper end of a lower shelf transfer device 30 which willbe described later. The upper support surface 62 a is at a positiondisplaced from the overhead transport vehicle 3 with respect to thehorizontal direction, and is located at a position higher than theoverhead transport vehicle 3.

The ceiling suspended shelf 6 has an upper side surface guide 63, whichfaces a side surface 83 of a FOUP 80. The presence of the upper sidesurface guide 63 is able to prevent a FOUP 80 that is placed in theupper shelf 62 from dropping, mispositioning, and the like. The upperside surface guide 63 is located at a position higher than the lower endof the rail 2. The upper side surface guide 63, however, is justrequired to be positioned higher than the upper support surface 62 a,and it is not always necessary that the upper side surface guide 63 belocated at a position higher than the lower end of the rail 2.

As shown in FIG. 5, the upper shelf 62 is able to rotate about apredetermined rotation axis, to thereby be opened and closed. Morespecifically, the upper shelf 62 is able to be brought into an openstate (chain lines in FIG. 5) where the upper shelf 62 is positionedoutside to allow a FOUP 80 to pass therethrough from below and a closedstate where the upper shelf 62 is positioned inside, and its opening ispartially or entirely closed to support a FOUP 80.

The ceiling suspended shelf 6 includes a switching mechanism 64 (FIG. 3and FIG. 4) to switch the state of the upper shelf 62 between the openstate and the closed state. The switching mechanism 64 includes a gear,a link, and the like, to transmit power received from an externalsource. In this preferred embodiment, the ceiling suspended shelf 6 doesnot have a driver to switch the state of the upper shelf 62, but powerreceived from the overhead transport vehicle 3 is used to switch thestate of the upper shelf 62 between the open state and the closed state.

To be specific, the overhead transport vehicle 3 includes a slideoperator 57 that operates the switching mechanism 64. As shown in FIG.4, the slide operator (operator) 57 is driven by an opening/closingmotor (driver) 58. The slide operator 57 is able to change its positionbetween a normal position and a pressing position. When the slideoperator 57 is in the normal position, the slide operator 57 is not incontact with the switching mechanism 64, and the upper shelf 62 is inthe closed state. When the slide operator 57 is in the pressingposition, the slide operator 57 operates the switching mechanism 64 toswitch the state of the upper shelf 62 to the open state.

In this preferred embodiment, switching between the open state and theclosed state is implemented by rotation of the upper shelf 62. Instead,switching between the open state and the closed state may be implementedby sliding of the upper shelf 62. Alternatively or additionally, theceiling suspended shelf 6 may be provided with a driver to switch thestate of the upper shelf 62.

According to the structure of the lower shelf 65, three FOUPs 80 areable to be placed in one compartment. In the lower shelf 65, as comparedto the upper shelf 62, a greater number of FOUPs 80 is able to be placedin one compartment (i.e., per unit length). This difference is caused bythe fact that upper shelf 62 and the lower shelf 65 are different fromeach other in terms of a mechanism to place a FOUP 80, details of whichwill be described later. The lower shelf 65 is located at a positionlower than the upper shelf 62. The level at which a lower supportsurface 65 a (the second support surface) of the lower shelf 65 supportsa FOUP 80 is lower than the level at which the overhead transportvehicle 3 supports a FOUP 80 while traveling, and is higher than thelevel at which the load port 5 supports a FOUP 80. The upper end of aFOUP 80 supported by the lower support surface 65 a is located below thelower end of a later-described upper shelf transfer device 40 (and morespecifically, below the lower end of the upper shelf transfer device 40after lateral movement thereof).

The lower shelf 65 is always in the closed state, and its state is notable to be switched unlike the upper shelf 62. In other words, the lowershelf 65 does not allow a FOUP 80 to pass therethrough in the up-downdirection. A specific structure of the lower shelf 65 is a shelf boardthat connects adjacent side plates 61.

The ceiling suspended shelf 6 has a lower side surface guide 66, whichfaces a side surface 83 of a FOUP 80. The presence of the lower sidesurface guide 66 is able to prevent a FOUP 80 that is placed in thelower shelf 65 from dropping, mispositioning, and the like.

The ceiling suspended shelf 6 has the anti-drop structure 67. Theanti-drop structure 67 is a net, a fence, a flat plate, or the like. Theanti-drop structure 67 is provided on the side (back side) of theceiling suspended shelf 6 opposite to the front side, where the frontside refers to the side facing the rail 2 (overhead transport vehicle3). In a plan view, the anti-drop structure 67 is provided on the sidefar from the rail 2 with respect to a direction perpendicular to therail 2. When a FOUP 80 placed in the upper shelf 62 or in the lowershelf 65 moves or falls toward the side away from the rail 2, theanti-drop structure 67 prevents dropping of the FOUP 80 by coming intocontact with the FOUP 80.

To reliably prevent the FOUP 80 from dropping, the anti-drop structure67 of this preferred embodiment covers a range from the lower end to theupper end of a FOUP 80 placed in the upper shelf 62 or in the lowershelf 65. In other words, the whole of the FOUP 80 overlaps theanti-drop structure 67 when viewed in a direction perpendicular to asurface of the anti-drop structure 67. In this preferred embodiment, theanti-drop structure 67 covers a range from the lower end of the uppershelf 62 to the upper end of a FOUP 80 placed in the lower shelf 65, butalternatively, the anti-drop structure 67 may be divided into a portioncorresponding to the upper shelf 62 side and a portion corresponding tothe lower shelf 65 side.

The anti-drop structure 67 is provided on the side opposite to theoverhead transport vehicle 3 across a FOUP 80 placed in the upper shelf62 or in the lower shelf 65. Accordingly, even if a FOUP 80 being placedinto the upper shelf 62 or the lower shelf 65 from the overheadtransport vehicle 3 comes into contact with another FOUP 80 alreadyplaced therein, dropping of the already placed FOUP 80 is able to beprevented.

The rail 2 includes a travel rail 2 a and an electricity supply rail 2b. The travel rail 2 a includes a travel support surface that supportsthe overhead transport vehicle 3 (and specifically a wheel 22 which willbe described later), and that allows the overhead transport vehicle 3 totravel. The electricity supply rail 2 b is provided on the lower side ofthe travel rail 2 a. The electricity supply rail 2 b, in which anelectricity supply line (not shown) is provided, supplies electric powerto the overhead transport vehicle 3.

The overhead transport vehicle 3 includes a travel motor 21, a wheel 22,and an electricity receiver 23, which allow the overhead transportvehicle 3 to travel along the rail 2. The travel motor 21 is provided inthe travel rail 2 a. The travel motor 21 generates power for theoverhead transport vehicle 3 to travel. The wheel 22 is in contact withthe above-described travel support surface of the travel rail 2 a. Thewheel 22 is driven into rotation by the travel motor 21. The electricityreceiver 23 is provided in the electricity supply rail 2 b. Theelectricity receiver 23, which is, for example, a pick-up coil thatreceives electric power from the electricity supply line of theelectricity supply rail 2 b, supplies electric power from theelectricity supply line to electric devices such as the travel motor 21.

As shown in FIG. 4, various drive sources and electric devices such asthe travel motor 21 are controlled by a control device 100. The controldevice 100 is implemented as a computer provided at an appropriateposition in the overhead transport vehicle 3. The control device 100includes an arithmetic processor such as a CPU, a memory such as a flashmemory or a hard disk, and an input/output to communicate with anexternal device or the like. The memory stores various programs and setvalues. The arithmetic processor reads out various programs, and thelike, from the memory, and controls operations of respective portions ofthe overhead transport vehicle 3.

As shown in FIG. 3, the overhead transport vehicle 3 includes a pair ofcoverings 3 a, which are provided one behind the other with respect to atravel direction. A structure to hold and transfer a FOUP 80 is providedbetween the pair of coverings 3 a.

As shown in FIG. 2, etc., the overhead transport vehicle 3 includes achuck (second holder) 51 and a holding base (first holder) 52, whichhold a FOUP 80. The chuck 51 grips and holds a flange portion 82 of anupper surface of the FOUP 80. The chuck 51 is switchable between holdingand not holding the flange portion 82.

The holding base 52 holds a bottom surface 81 of the FOUP 80. To bespecific, as shown in FIG. 5, FIG. 6, FIG. 9, etc., a holding surface 52a (a surface coming into contact with the bottom surface 81) of theholding base 52 has a plurality of insertion pins 52 b provided atpredetermined positions. On the other hand, the bottom surface 81 of theFOUP 80 has a recess 81 a having a predetermined shape, as shown in FIG.6. The positions where the plurality of insertion pins 52 b are formedcorrespond to the shape of the recess 81 a. Accordingly, by insertingthe insertion pins 52 b into the recess 81 a, the FOUP 80 is able to bestably held. Provided near the holding base 52 is a guide 53 to preventmispositioning, and the like, of the FOUP 80.

While the overhead transport vehicle 3 is traveling, the holding base 52holds a FOUP 80. In the following description, a position where theoverhead transport vehicle 3 holds a FOUP 80 while traveling will bereferred to as a hold position. Holding a FOUP 80 by the holding base 52is able to stabilize the FOUP 80. Alternatively, while the overheadtransport vehicle 3 is traveling, a FOUP 80 may be held by both thechuck 51 and the holding base 52 or by the chuck 51 alone.

The overhead transport vehicle 3 includes: the lower shelf transferdevice (second transfer device) 30 that moves a FOUP 80 located in thehold position, to place the FOUP 80 into the lower shelf 65 (downwardtransfer position); and the upper shelf transfer device (first transferdevice) 40 that moves a FOUP 80 located in the hold position, to placethe FOUP 80 into the upper shelf 62 (upper transfer position). The lowershelf transfer device 30 is used also to place a FOUP 80 into the loadport 5.

First, the lower shelf transfer device 30 will be described. The lowershelf transfer device 30 is able to move the chuck 51 in the lateraldirection (horizontal direction) (third movement), and also able to movethe chuck 51 in the downward direction (fourth movement). As shown inFIG. 2, FIG. 5, and the like, the lower shelf transfer device 30includes a lateral transfer mechanism 31 and a downward transfermechanism 33. As shown in FIG. 4, the lateral transfer mechanism 31 isdriven by a lateral transfer motor 32, and the downward transfermechanism 33 is driven by a downward transfer motor 34.

The lateral transfer mechanism 31 is able to move the chuck 51 in thelateral direction (specifically, in a direction perpendicular to theforward direction in a plan view). More specifically, the lateraltransfer mechanism 31 includes a plurality of movable plates that areable to move in the lateral direction. The chuck 51 is able to moveintegrally with the lowermost movable plate. The lateral transfermechanism 31 uses power from the lateral transfer motor 32, to slideeach of the movable plates in the lateral direction as shown in FIG. 5,thereby causing the chuck 51 supported by the lateral transfer mechanism31 to move in the lateral direction. As a result, the FOUP 80 is able tobe moved in the lateral direction. In this preferred embodiment, theupper support surface 62 a is located at a position higher than theupper end of the lateral transfer mechanism 31, and therefore, duringlateral movement of the lateral transfer mechanism 31, the lateraltransfer mechanism 31 does not come into contact with either the uppershelf 62 and the FOUP 80 supported by the upper shelf 62, for example.

The downward transfer mechanism 33 is able to move the chuck 51 in thedownward direction. The downward transfer mechanism 33 is a hoist, forexample, and is able to lower and retrieve a suspension structure suchas a wire, as shown in FIG. 5, by using power from the downward transfermotor 34. Accordingly, the FOUP 80 is able to be moved in the up-downdirection.

The downward transfer mechanism 33 is able to move integrally with thelowermost movable plate of the lateral transfer mechanism 31. Thus,lateral movement of the lateral transfer mechanism 31 and downwardmovement of the downward transfer mechanism 33 are able to becompatible. Accordingly, a transfer position to which the lower shelftransfer device 30 is able to transfer a FOUP 80 is able to be locatednot only directly below and directly beside but also obliquely below.

Here, while a FOUP 80 is held by the holding base 52, interference amongcomponents occurs to disable movement of the FOUP 80 by the lower shelftransfer device 30 (especially the downward transfer mechanism 33). Inthis preferred embodiment, therefore, before the lower shelf transferdevice 30 moving the FOUP 80, the holding base 52 is removed from theFOUP 80 and retracted from the lower side of the FOUP 80 (from atrajectory of the chuck 51 being moved downward by the lower shelftransfer device 30). For this retraction, the overhead transport vehicle3 includes a retraction mechanism 55 and a retraction motor 56, as shownin FIG. 6.

The retraction mechanism 55 includes a link that is operated with powerfrom the retraction motor 56. The link is rotatably coupled to the guide53. The holding base 52 is able to move integrally with the guide 53 ina predetermined trajectory. Accordingly, by operating the link of theretraction mechanism 55 with power from the retraction motor 56, theholding base 52 and the guide 53 are able to be moved to the back sideof the FOUP 80, that is, are able to be retracted from a position belowthe FOUP 80. Here, it may be acceptable that a temporary shelf (UTB:Under Track Buffer) suspended from the ceiling 7 is additionallyprovided below the rail 2. The temporary shelf is in a positionoverlapping the rail 2 in a plan view, and is installed with a phaseshift from the load port 5 with respect to a direction in which the rail2 extends. The second transfer device is able to transfer a FOUP 80 tothe temporary shelf.

As described above, while the overhead transport vehicle 3 is traveling,a FOUP 80 is held by the holding base 52 and is not held by the chuck51. To transfer the FOUP 80 to the lower shelf 65 or to the load port 5after the overhead transport vehicle 3 stops, the chuck 51 holds theFOUP 80, and then the retraction motor 56 is driven to remove theholding base 52 from the FOUP 80. After that, transfer is performed bythe lower shelf transfer device 30.

Next, the upper shelf transfer device 40 will be described mainly withreference to FIG. 7 and FIG. 8.

As shown in FIG. 7 and FIG. 8, the upper shelf transfer device 40 isprovided in a space between the covering 3 a and a FOUP 80 with respectto the travel direction. The upper shelf transfer device 40 is able tomove the holding base 52 in the lateral direction (first movement), andalso able to move the holding base 52 in the upward direction (secondmovement). In the first movement, it is sufficient that the movingdirection includes the lateral direction. Thus, directions other thanthe direct lateral direction are allowed. The same applies to the secondand subsequent movements. As shown in FIG. 8, the upper shelf transferdevice 40 includes a lateral slide mechanism 41 and an upward slidemechanism 43. As shown in FIG. 4, the lateral slide mechanism 41 isdriven by a lateral slide motor 42, and the upward slide mechanism 43 isdriven by an upward slide motor 44.

The lateral slide mechanism 41 is able to move the holding base 52 inthe lateral direction (specifically, in a direction perpendicular to theforward direction in a plan view). More specifically, the lateral slidemechanism 41 includes a plurality of movable plates that are able tomove in the lateral direction. The lateral slide mechanism 41 includesthree movable plates that are coupled to one another by a belt or achain. The holding base 52 is able to move integrally with the innermostmovable plate. The lateral slide mechanism 41 uses power of the lateralslide motor 42, to slide each of the movable plates in the lateraldirection as shown in FIG. 8, thereby causing the holding base 52supported by the lateral slide mechanism 41 to move in the lateraldirection. As a result, the FOUP 80 is able to be moved in the lateraldirection.

The upward slide mechanism 43 is able to move the holding base 52 in theupward direction. Specifically, the upward slide mechanism 43 includes aplurality of movable plates that are able to move in the upwarddirection. The holding base 52 is able to move integrally with theinnermost movable plate. The upward slide mechanism 43 uses power fromthe upward slide motor 44, to slide each of the movable plates in theupward direction as shown in FIG. 8, thereby causing the holding base 52supported by the upward slide mechanism 43 to move in the upwarddirection. As a result, the FOUP 80 is able to be moved in the upwarddirection. In this preferred embodiment, while transferring the FOUP 80to the upper shelf 62, the upward slide mechanism 43 keeps to bepositioned on a side surface of the FOUP 80. Therefore, the uppershelves 62 are spaced away from each other by a large interval, in orderto avoid interference of the upward slide mechanism 43 with another FOUP80. Accordingly, the number of FOUPs 80 that are able to be placed inone compartment of the upper shelf 62 is different from that of thelower shelf 65.

Next, referring to FIG. 7 to FIG. 9, how a FOUP 80 in the hold positionis transferred to the upper shelf 62 will be described.

First, the overhead transport vehicle 3 stops on the lateral side of anupper shelf 62 defining and functioning as a transfer destination (theupper drawing in FIG. 7). Then, the overhead transport vehicle 3 movesthe slide operator 57 to the pressing position, and the upper shelf 62is switched from the closed state to the open state (the lower drawingin FIG. 7). In a case where, unlike the present preferred embodiment,the FOUP 80 is held by the chuck 51 alone while the overhead transportvehicle 3 is traveling; the chuck 51 is detached, and the FOUP 80 isheld by the holding base 52.

Then, the overhead transport vehicle 3 operates the lateral slidemechanism 41, to move the FOUP 80 in the lateral direction (the upperdrawing in FIG. 8). At this time, the FOUP 80 is positioned directlybelow the upper shelf 62. Then, the overhead transport vehicle 3operates the upward slide mechanism 43, to move the FOUP 80 in theupward direction (the lower drawing in FIG. 8). At this time, to provideappropriate rotation of the upper shelf 62, the FOUP 80 is positionedabove the upper transfer position. In this preferred embodiment,completion of the lateral movement by the lateral slide mechanism 41 isfollowed by upward movement by the upward slide mechanism 43.Alternatively, the upward movement is able to be started beforecompletion of the lateral movement. As described above, after lateralmovement of the upper shelf transfer device 40 (lateral slide mechanism41), its lower end is located above the upper end of a FOUP 80 supportedby the lower shelf 65 (more specifically, is located at a positionoverlapping the upper end of the FOUP 80 in a plan view). Accordingly,interference of the lateral slide mechanism 41 with the FOUP 80 placedin the lower shelf 65 is prevented.

Then, the overhead transport vehicle 3 moves the slide operator 57 tothe normal position, and the upper shelf 62 is switched from the openstate to the closed state (the upper drawing in FIG. 9). Then, theoverhead transport vehicle 3 starts an operation to store the upwardslide mechanism 43 and the lateral slide mechanism 41 into the overheadtransport vehicle 3 (the lower drawing in FIG. 9).

Since the overhead transport vehicle 3 includes the upper shelf transferdevice 40 and the ceiling suspended shelf 6 includes the upper shelf 62,a FOUP 80 is able to be placed at a high position (in this preferredembodiment, at the same level as that of the rail 2). Accordingly, moreeffective use of a space in the factory is achieved, particularly withrespect to a space directly beside the rail 2, which has not previouslybeen effectively used. Especially in a factory to manufacturesemiconductor products, a high cleanliness in the factory is required,and therefore the equipment cost increases as the space in the factoryincreases. Thus, the transport system 1 of this preferred embodiment isparticularly effective in a factory to manufacture semiconductorproducts.

All of the overhead transport vehicles 3 included in the transportsystem 1 may include the upper shelf transfer devices 40, or only aportion of the overhead transport vehicles 3 may include the upper shelftransfer device(s) 40. In the latter case, the lower shelf transferdevices 30 may be included in the portion of the overhead transportvehicles 3 and the lower shelf transfer devices 30 included in the restof them have identical or similar features. Accordingly, the lower shelf65 is able to be commonly used by the portion and the rest of theoverhead transport vehicles 3.

Next, referring to FIG. 10 and FIG. 11, a second preferred embodimentwill be described.

In the first preferred embodiment described above, the upper shelftransfer device 40 includes the lateral slide mechanism 41 and thelateral slide motor 42. The second preferred embodiment, on the otherhand, has an upper shelf transfer device 90 is an arm mechanismincluding a plurality of arms that are rotatably coupled to one another.

To be specific, as shown in FIG. 11, the upper shelf transfer device 90includes a first arm 91, a second arm 93, and a third arm 95 provided inthis order from the side close to the overhead transport vehicle 3. Asshown in FIG. 10, the first arm 91 is driven by a first arm motor 92,the second arm 93 is driven by a second arm motor 94, and the third arm95 is driven by a third arm motor 96. Thus, the arms are able to operateindependently of one another.

The base end of the first arm 91 is coupled to the overhead transportvehicle 3, and the distal end of the first arm 91 is rotatably coupledto the base end of the second arm 93. The distal end of the second arm93 is rotatably coupled to the base end of the third arm 95. Coupled tothe distal end of the third arm 95 is a first holder 97.

To transfer a FOUP 80 by the upper shelf transfer device 90, adjustingthe rotation angles of the first arm 91, the second arm 93, and thethird arm 95 are able to move the first holder 97 to the upper shelf 62while keeping the first holder 97 horizontal, as shown in FIG. 11. Morespecifically, first, the FOUP 80 is held by the overhead transportvehicle 3, and in this state, the first arm 91 is rotated and the firstholder 97 moves mainly in the lateral direction (first movement; theupper drawing in FIG. 11). Then, as the rotation angle of the first arm91 increases, the first holder 97 moves mainly in the upward direction(second movement; the lower drawing in FIG. 11). Since the rotation ofthe first arm 91 changes the rotation angles of the second arm 93 andthe third arm 95, the second arm 93 and the third arm 95 are rotated toset the first holder 97 to be horizontal.

Next, referring to FIG. 12, a third preferred embodiment of the presentinvention will be described.

In the first preferred embodiment, the upper shelf transfer device 40moves a FOUP 80 with the insertion pins 52 b of the holding base 52being received in the recess 81 a of the FOUP 80. Instead, insertionpins 62 b (FIG. 12) may be provided on the upper support surface 62 a ofthe upper shelf 62. By inserting the insertion pins 62 b into the recess81 a of the FOUP 80, the posture of the FOUP 80 placed in the uppershelf 62 is able to be stabilized. Instead of or in addition to theupper shelf 62, the lower shelf may have insertion pins 65 b provided onits lower support surface 65 a, and the insertion pins 65 b are receivedin the recess 81 a of the FOUP 80.

The recess 81 a of the FOUP 80 may include a first recess to receive theinsertion pins 52 b of the holding base 52, and a second recess toreceive the insertion pins 62 b of the upper shelf 62 (or the insertionpins 65 b of the lower shelf 65). Accordingly, the posture of the FOUP80 is able to be stabilized both during and after upward transfer of theFOUP 80. The features of the first to third preferred embodiments areable to be combined as appropriate. For example, the anti-drop structure67 of the first preferred embodiment is applicable to the secondpreferred embodiment or the third preferred embodiment.

Next, referring to FIG. 13 to FIG. 18, fourth to seventh preferredembodiments will be described. In the fourth to seventh preferredembodiments, a rotational operator (operator) 59 is used instead of theslide operator 57, to supply a driving force to the upper shelf 62.First, referring to FIG. 13 and FIG. 14, features shared by the fourthto seventh preferred embodiments will be described.

As shown in FIG. 13, an overhead transport vehicle 3 according to eachof these preferred embodiments includes a motor mount 45 in addition tothe opening/closing motor 58 and the rotational operator 59 describedabove. The motor mount 45 is attached to the upper shelf transfer device40. The motor mount 45 is attached to a portion of the upper shelftransfer device 40, the portion being moved in the first movementinvolving lateral movement of the holding base 52 (FOUP 80) but beingnot moved in the second movement involving upward movement of theholding base 52. Accordingly, the rotational operator 59 moves in thelateral direction in the first movement. Although these preferredembodiments have the motor mount 45 attached at only one side withrespect to the forward direction, it is acceptable that the motor mounts45 are attached on both sides.

Mounted to the motor mount 45 are the opening/closing motor 58 and therotational operator 59. Like the foregoing preferred embodiment, theopening/closing motor 58 generates a driving force to switch the stateof the upper shelf 62 between the open state and the closed state. Theopening/closing motor 58 is able to control the rotation direction andthe amount of rotation. The rotational operator 59 is rotated with adriving force generated by the opening/closing motor 58. Similarly tothe slide operator 57, the rotational operator 59 transmits the drivingforce to the upper shelf 62 side. The motor mount 45, theopening/closing motor 58, and the rotational operator 59 are provided atpositions (for example, outside the upward slide mechanism 43) thatavoid interference with the second movement of the upward slidemechanism 43.

In these preferred embodiments, two opening/closing motors 58 and tworotational operators 59 are provided side by side in a direction(left-right direction) perpendicular to both the forward direction andthe up-down direction. The opening/closing motor 58 and the rotationaloperator 59 on one side in the left-right direction are used to transfera FOUP 80 to the upper shelf 62 located on one side in the left-rightdirection, while the opening/closing motor 58 and the rotationaloperator 59 on the other side in the left-right direction are used totransfer a FOUP 80 to the upper shelf 62 located on the other side inthe left-right direction. Instead, it is acceptable that anopening/closing motor 58 and a rotational operator 59 are commonly usedin transfer of a FOUP 80 to either of the upper shelves 62 on one sideand the other side in the left-right direction.

As shown in FIG. 14, the upper shelf 62 includes a first shaft 71, afirst arm 72, a first support portion 73, a second shaft 75, a secondarm 76, and a second support portion 77.

The first shaft 71 is rotatably mounted to a fixed portion (an immovableportion, e.g., the side plate 61 in the foregoing preferred embodiment)of the upper shelf 62. The first arm 72 is able to rotate integrallywith the first shaft 71 in the same direction as the first shaft 71. Thefirst shaft 71 is fixed to one end portion of the first arm 72, whilethe first support portion 73 is fixed to the other end portion of thefirst arm 72. The first shaft 71 includes a pair of first shafts 71, andthe first arm 72 includes a pair of first arms 72. The upper shelf 62includes the first support portion 73, which connects the pair of firstarms 72. The first support portion 73 is a portion that supports a FOUP80. The first support portion 73 may be shaped like a rod or flat plate.

The second shaft 75, the second arm 76, and the second support portion77 have features that are identical or symmetrical to the features ofthe first shaft 71, the first arm 72, and the first support portion 73.Thus, a FOUP 80 is supported by the first support portion 73 and thesecond support portion 77.

Accordingly, rotation of the first shafts 71 causes the first arms 72and the first support portion 73 to rotate integrally. Rotation of thesecond shafts 75 causes the second arms 76 and the second supportportion 77 to rotate integrally. Accordingly, the state of the uppershelf 62 is able to be switched between the closed state (solid lines)and the open state (chain lines).

Accordingly, a driving force received from the overhead transportvehicle 3 (a driving force received from the outside of the upper shelf62) is used to rotate the first shafts 71 and the second shafts 75. Toswitch between the closed state and the open state, the first shafts 71and the second shafts 75 may be rotated in different directions.Rotating the first shafts 71 and the second shafts 75 in the samedirection causes, for example, the first support portion 73 to rotateupward while causing the second support portion 77 to rotate downward.In this case, a large space is occupied in the up-down direction. Thefirst shafts 71 and the second shafts 75 are able to in the samedirection, for example, to simplify the switching mechanism 64.

In these preferred embodiments, the driving force from the overheadtransport vehicle 3 is transmitted to the first shaft 71 through areceiving portion 101, a receiving shaft 102, a first bevel gear 103,and a second bevel gear 104, which are included in the switchingmechanism 64. The receiving portion 101 is rotatable about the receivingshaft 102 defining and functioning as the rotation axis. The receivingportion 101 is located at a position corresponding to a location of therotational operator 59 after the first movement. Accordingly, therotational operator 59 is rotated after the first movement, and thereceiving portion 101 and the receiving shaft 102 are rotated inaccordance with the rotation direction and the amount of rotation of therotational operator 59.

The first bevel gear 103 is fixed to the receiving shaft 102. The secondbevel gear 104 is fixed to the first shaft 71. The first bevel gear 103and the second bevel gear 104 are meshed with each other. Accordingly,the driving force is able to transmit from the rotational operator 59 tothe first shaft 71 through the first bevel gear 103, the second bevelgear 104, and the like. Changing the rotation direction of theopening/closing motor 58 is able to change the rotation direction of thefirst shaft 71. The transmission of the driving force using thereceiving portion 101, the receiving shaft 102, the first bevel gear103, and the second bevel gear 104 is just an example, and is able to bealtered as appropriate.

In these preferred embodiments, the driving force used to rotate thefirst shafts 71 is further transmitted to the second shafts 75 by theswitching mechanism 64, and the second shafts 75 are rotated in thedirection reverse to the rotation direction of the first shafts 71.Thus, the first shafts 71 and the second shafts 75 are able to be drivento switch the state of the upper shelf 62 from the open state to theclosed state by using the single driver. A specific structure of theswitching mechanism 64 varies among the preferred embodiments.

In the fourth to sixth preferred embodiments, the state of the uppershelf 62 is able to be switched from the closed state to the open stateby rotating the opening/closing motor 58 in the reverse direction,because it causes the first shafts 71 and the second shafts 75 to rotatein directions reverse to the directions in which they rotate to switchfrom the open state to the closed state. In the seventh preferredembodiment, instead of rotating the opening/closing motor 58 in thereverse direction, the other rotational operator 59 is used to rotatethe second shafts 75, as will be described later. Only in the seventhpreferred embodiment, features corresponding to the receiving portion101, the receiving shaft 102, the first bevel gear 103, and the secondbevel gear 104 are provided not only to the first shaft 71 but also tothe second shaft 75.

Next, referring to FIG. 15, the switching mechanism 64 of the fourthpreferred embodiment will be described.

The switching mechanism 64 of the fourth preferred embodiment includes alink support portion 111 and a coupling link mechanism 110. The linksupport portion 111 supports the first shaft 71, the second shaft 75,the coupling link mechanism 110, and the like. The link support portion111 is not moved in conjunction with the first shaft 71, the secondshaft 75, the coupling link mechanism 110, and the like.

The coupling link mechanism 110 is a mechanism that couples the firstshaft 71 to the second shaft 75. The coupling link mechanism 110includes a first coupling link 112, a first shaft link 113, an auxiliarylink 114, a common link 115, a second coupling link 116, a second shaftlink 117, and an auxiliary link 118.

The first coupling link 112 is coupled to the first shaft link 113, theauxiliary link 114, and the common link 115. The first shaft link 113,which is fixed to the first shaft 71 via a through hole formed in thelink support portion 111, rotates integrally with the first shaft 71.Thus, as the first shaft 71 is driven, the first coupling link 112 ismoved. The auxiliary link 114 is attached to the link support portion111. The common link 115 is inserted into an opening 112 a in the shapeof an elongated hole formed in the first coupling link 112. In thispreferred embodiment, the first shaft link 113, the auxiliary link 114,and the common link 115 have equal turning radii. Thus, the firstcoupling link 112 moves without changing its direction(parallel-translation movement).

The second coupling link 116 is coupled to the second shaft link 117,the auxiliary link 118, and the common link 115. The second couplinglink 116, the second shaft link 117, and the auxiliary link 118 areaxially symmetrical to the first coupling link 112, the first shaft link113, and the auxiliary link 114. The axis of the axial symmetry is aline that passes through the middle point of a line segment connectingthe first shaft 71 to the second shaft 75 and that is perpendicular tothe line segment. The common link 115 is inserted into an opening 116 aof the second coupling link 116. The second coupling link 116 isoperated by receiving a driving force via the common link 115. Theauxiliary link 118 and the second shaft link 117 are rotatedaccordingly. Movements of the second coupling link 116, the second shaftlink 117, and the auxiliary link 118 are axially symmetrical tomovements of the first coupling link 112, the first shaft link 113, andthe auxiliary link 114 with respect to the aforementioned axis.Therefore, the rotation direction of the first shaft 71 is differentfrom the rotation direction of the second shaft 75.

A further description will be provided to a change of the rotationdirections of the first shaft 71 and the second shaft 75 upontransmission of the driving force from the first shaft 71 to the secondshaft 75. In the upper drawing in FIG. 15, a position where the firstcoupling link 112 is coupled to the first shaft link 113 is locatedlower than the first shaft 71 and more inward than the first shaft 71.Naturally, a position where the second coupling link 116 is coupled tothe second shaft link 117 is located lower than the second shaft 75 andmore inward than the second shaft 75. If an upward force acts on boththe first shaft link 113 and the second shaft link 117, the first shaftlink 113 and the second shaft link 117 rotate upward while passingthrough the inside (rotate in different directions).

Accordingly, with use of the coupling link mechanism 110, just rotatingthe first shaft 71 toward one side is able to rotate the second shaft 75toward the other side. As a result, the first support portion 73 and thesecond support portion 77 are able to be rotated outward as shown inFIG. 15, and the state of the upper shelf 62 is able to be switched fromthe closed state to the open state. Likewise, by rotating the firstshaft 71 in another direction, the state of the upper shelf 62 is ableto be switched from the open state to the closed state.

The first coupling link 112 is a substantially L-shaped structureincluding a portion that retracts (extends) upward from its portioncoupled to the first shaft link 113. The second coupling link 116includes the same or similar features. Thus, in the coupling linkmechanism 110, a space appears in a region around the line segmentconnecting the first shaft 71 to the second shaft 75. By this,interference of the upper shelf 62 with the overhead transport vehicle 3is prevented. Features to provide upward retraction of the firstcoupling link 112 and the second coupling link 116 may not be necessarydepend on the overhead transport vehicle 3.

After switching the state of the upper shelf 62, the rotational operator59 is away from the upper shelf 62. The upper shelf 62, therefore, maybe provided with a stopper or the like to maintain the current state(for maintaining the state until a force of a predetermined or moremagnitude is applied).

Next, referring to FIG. 16, the switching mechanism 64 of the fifthpreferred embodiment will be described.

In the foregoing fourth preferred embodiment, the first shaft link 113and the second shaft link 117 are coupled via two links (the firstcoupling link 112 and the second coupling link 116). In the fifthpreferred embodiment, a first shaft link 122 and a second shaft link 123are coupled via a single link (coupling link 124). The features of thefirst shaft link 122 and the second shaft link 123 are identical orsimilar to the features of the fourth preferred embodiment.

A portion of the coupling link 124 on the first shaft 71 side isrotatably coupled to the first shaft link 122, and a portion thereof onthe second shaft 75 side is rotatably coupled to the second shaft link123. The coupling link 124 is able to retract upward, similar to thefourth preferred embodiment. The coupling link 124 is supported by alink support portion 121 via the first shaft link 122 and the secondshaft link 123, similarly to the fourth preferred embodiment. Fixed tothe link support portion 121 is a stopping plate 125 to prevent thecoupling link 124 from shaking in the axial direction of the first shaft71, etc. The stopping plate 125 normally does not cramp the couplinglink 124. Only when the coupling link 124 largely moves in the axialdirection of the first shaft 71, etc., the stopping plate 125 comes intocontact with the coupling link 124 to prevent more movement.

As the first shaft 71 is rotated, the first shaft link 122 is integrallyrotated in the same direction. As the first shaft link 122 is rotated,the coupling link 124 operates and the second shaft link 123 is rotated.Consequently, the second shaft 75 is rotated in the direction reverse tothe rotation direction of the first shaft 71.

Depending on the shape and coupling position of the coupling link 124,the first shaft 71 and the second shaft 75 may be rotated in the samedirection. In this preferred embodiment, however, the second shaft 75receives a driving force from the first shaft 71, to thereby be rotatedin the direction reverse to the rotation direction of the first shaft71. For example, in the upper drawing in FIG. 16, rotation of the firstshaft 71 causes a coupling portion between the first shaft link 122 andthe coupling link 124 to be rotated toward the inside while passingthrough the lower side of the first shaft 71. This driving force istransmitted to the second shaft link 123 via the coupling link 124. Acoupling portion between the second shaft link 123 and the coupling link124 is located above the second shaft 75, and therefore is rotatedtoward the outside while passing through the upper side of the secondshaft 75. Consequently, the first shaft 71 and the second shaft 75 arerotated in different directions.

As thus far described, with use of the coupling link 124, etc., justrotating the first shaft 71 toward one side is able to rotate the secondshaft 75 toward the other side. As a result, the first support portion73 and the second support portion 77 are able to be rotated outward asshown in FIG. 16, and the state of the upper shelf 62 is able to beswitched from the closed state to the open state. Likewise, by rotatingthe first shaft 71 in another direction, the state of the upper shelf 62is able to be switched from the open state to the closed state.

Next, referring to FIG. 17, the switching mechanism 64 of the sixthpreferred embodiment will be described.

In the sixth preferred embodiment, a structure including belts andpulleys is used to transmit a driving force from the first shaft 71 tothe second shaft 75. To be specific, the switching mechanism 64 of thesixth preferred embodiment includes a first belt 131 and a second belt135.

The first belt 131 is wound around a drive pulley 132 and a first pulley133. The drive pulley 132, which is fixed to the first shaft 71, rotatesintegrally with the first shaft 71. Rotation of the first shaft 71defines and functions as a driving force to move the first belt 131. Thefirst pulley 133 is located at a position between the first shaft 71 andthe second shaft 75, the position being located higher than the firstshaft 71 and the second shaft 75. The switching mechanism 64 is able topartially retract upward, similarly to the fourth and fifth preferredembodiments. The switching mechanism 64 also includes a first gear 134,which rotates integrally with the first pulley 133. Thus, rotation ofthe first shaft 71 causes rotation of the first gear 134.

The first gear 134 is meshed with a second gear 136 provided near thefirst gear 134. Accordingly, the second gear 136 is rotated in thedirection reverse to the rotation direction of the first gear 134. Theswitching mechanism 64 also includes a second pulley 137, which rotatesintegrally with the second gear 136. The second belt 135 is wound aroundthe second pulley 137 and a driven pulley 138. The driven pulley 138,which is fixed to the second shaft 75, rotates integrally with thesecond shaft 75.

Accordingly, rotation of the second shaft 75 is able to be caused byrotation of the first shaft 71. Since the first gear 134 and the secondgear 136 are provided midway, the rotation direction of the second shaft75 is reverse to that of the first shaft 71. As a result, the firstsupport portion 73 and the second support portion 77 are able to berotated outward as shown in FIG. 17, and the state of the upper shelf 62is able to be switched from the closed state to the open state.Likewise, by rotating the first shaft 71 in another direction, the stateof the upper shelf 62 is able to be switched from the open state to theclosed state.

In the sixth preferred embodiment, the first gear 134 and the secondgear 136 are directly meshed with each other; however, they may bemeshed with each other via an even number of gears.

Next, referring to FIG. 18, the switching mechanism 64 of the seventhpreferred embodiment will be described.

The switching mechanism 64 of the seventh preferred embodiment transmitsa driving force by using rotation of a reel retrieving a belt.Specifically, the switching mechanism 64 includes a coupling belt 141, afirst reel 142, and a second reel 143.

According to the structure of the first reel 142, the coupling belt 141is able to be wound thereon. The first reel 142, which is fixed to thefirst shaft 71, rotates integrally with the first shaft 71. Accordingly,rotating the first shaft 71 in a first direction by using the rotationaloperator 59 is able to wind the coupling belt 141.

The coupling belt 141 retracts upward from the first reel 142, and thenis wound on the second reel 143. The switching mechanism 64 is able topartially retract upward, similar to the fourth to sixth preferredembodiments.

According to the structure of the second reel 143, the coupling belt 141is able to be wound thereon. The second reel 143, which is fixed to thesecond shaft 75, rotates integrally with the second shaft 75. As shownin FIG. 18, a direction in which the coupling belt 141 is wound on thefirst reel 142 and a direction in which the coupling belt 141 is woundon the second reel 143 are the same. Accordingly, a rotation directionof the first reel 142 when the coupling belt 141 is wound is differentfrom a rotation direction of the second reel 143 when the coupling belt141 is pulled out.

As the first shaft 71 is rotated in the first direction, and the firstreel 142 winds the coupling belt 141 as described above, the second reel143 is rotated in a direction to pull out the coupling belt 141. Inother words, the first shaft 71 and the second shaft 75 are rotated indifferent directions.

On the other hand, rotating the first shaft 71 in a second direction(the direction reverse to the first direction) does not always cause thecoupling belt 141 to be wound onto the second reel 143. A driving forceof the first shaft 71 is not transmitted to the second shaft 75. In theseventh preferred embodiment, therefore, not only the rotationaloperator 59 to drive the first shaft 71 but also a rotational operator59 to drive the second shaft 75 is provided. In addition, providedbetween the rotational operator 59 and the second shaft 75 are areceiving portion 101, a receiving shaft 102, a first bevel gear 103, asecond bevel gear 104, and the like, as described above.

Accordingly, the second shaft 75, in addition to the first shaft 71, isable to be driven into rotation. As shown in FIG. 18, as the rotationaloperator 59 rotates the second shaft 75 and the second reel 143 isrotated in a direction wind the coupling belt 141, the coupling belt 141is pulled out from the first reel 142. The coupling belt 141 is able tobe rotated accordingly. In this case as well, the first shaft 71 and thesecond shaft 75 are rotated in different directions. As a result, thefirst support portion 73 and the second support portion 77 are able tobe rotated outward, and the state of the upper shelf 62 is able to beswitched from the closed state to the open state. As the rotationaloperator 59 rotates the first shaft 71 and the first reel 142 is rotatedin a direction to wind the coupling belt 141, the state of the uppershelf 62 is able to be switched from the open state to the closed state.

As thus far described, the ceiling suspended shelf 6 is a shelf wherethe overhead transport vehicle 3 temporarily places a FOUP 80 intransporting the FOUP 80 to the target position (load port 5), theoverhead transport vehicle 3 transporting the FOUP 80 by traveling alongthe rail 2 while being suspended, the rail being provided on the ceiling7 of the building. The ceiling suspended shelf 6 is suspended from theceiling 7. The ceiling suspended shelf 6 includes the upper shelf 62including the upper support surface 62 a to support the FOUP 80. Thelevel of the upper support surface 62 a is substantially the same as thelevel of the rail 2.

Accordingly, the FOUP 80 is able to be placed at a high position in aspace that has conventionally not been available to place a FOUP 80,thus achieving more effective use of a space in the building.

In the foregoing preferred embodiments, the ceiling suspended shelf 6includes the switching mechanism 64 to switch the state of the uppershelf 62 between the open state that allows the FOUP 80 to pass frombelow to above the upper shelf 62, and the closed state that allows theupper shelf 62 to support the FOUP 80 and does not allow the FOUP 80 topass from below to above the upper shelf 62.

Accordingly, an operation to place the FOUP 80 in the upper shelf 62,which locates the FOUP 80 at a high position, is able to be implementedfrom below. Thus, the operation to place the FOUP 80 is able to besimple.

In the foregoing preferred embodiments, the switching mechanism 64 ofthe ceiling suspended shelf 6 switches between the open state and theclosed state by using a driving force received from outside (from theoverhead transport vehicle 3).

In the fourth to seventh preferred embodiments, the upper shelf 62 ofthe ceiling suspended shelf 6 includes the first shaft 71, the firstsupport portion 73, the second shaft 75, and the second support portion77. The first shaft 71 is able to rotate. The first support portion 73rotates integrally with the first shaft 71. The second shaft 75 is ableto rotate, and its axial center is different to that of the first shaft71. The second support portion 77 rotates integrally with the secondshaft 75. The switching mechanism 64 switches between the open state andthe closed state by transmitting to the first shaft 71 an externaldriving force as a rotational force while transmitting to the secondshaft 75 an external driving force as a rotational force in thedirection reverse to the rotational force transmitted to the first shaft71.

Accordingly, it is not necessary to independently drive the first shaft71 and the second shaft 75, which simplifies a drive system. If thefirst shaft 71 and the second shaft 75 were rotated in the samedirection, the first support portion 73 would be rotated upward whilethe second support portion 77 would be rotated downward, resulting in alarger space occupied in the up-down direction. In this respect,rotating the first shaft 71 and the second shaft 75 in differentdirections causes the first support portion 73 and the second supportportion 77 to move up or down in the same direction, which contributesto a reduction of an occupied space in the up-down direction.

In the fourth preferred embodiment, the switching mechanism 64 of theceiling suspended shelf 6 includes the coupling link mechanism 110 thatcouples the first shaft 71 to the second shaft 75. The coupling linkmechanism 110 includes the first coupling link 112 and the secondcoupling link 116. The first coupling link 112 is positioned on the sideclose to the first shaft 71. The second coupling link 116 is positionedon the side close to the second shaft 75, is coupled to the firstcoupling link 112, and rotates in the direction reverse to the rotationdirection of the first coupling link 112.

Accordingly, by using the links, the first shaft 71 and the second shaft75 are able to be rotated in different directions.

In the fifth preferred embodiment, the switching mechanism 64 of theceiling suspended shelf 6 includes the first shaft link 122, the secondshaft link 123, and the coupling link 124. The first shaft link 122rotates integrally with the first shaft link 122. The second shaft link123 rotates integrally with the second shaft 75. The coupling link 124couples the first shaft link 122 to the second shaft link 123 and thefirst shaft link 122 and the second shaft link 123 rotate in differentdirections.

Accordingly, by mainly using the single coupling link 124, the firstshaft link 122 and the second shaft link 123 are able to be rotated indifferent directions, thus providing a simple mechanism.

In the sixth preferred embodiment, the switching mechanism 64 of theceiling suspended shelf 6 includes the first pulley 133, the first belt131, the first gear 134, the second gear 136, the second pulley 137, andthe second belt 135. The first belt 131 is wound around the first pulley133, and rotates the first shaft 71. The first gear 134 rotatesintegrally with the first pulley 133 in the same direction as the firstpulley 133. The second gear 136 is meshed with the first gear 134, tothereby be rotated in the direction reverse to the rotation direction ofthe first gear 134. The second pulley 137 rotates integrally with thesecond gear 136 in the same direction as the second gear 136. The secondbelt 135 is wound around the second pulley 137, and rotates the secondshaft 75.

Accordingly, by using the belts and pulleys, the first shaft 71 and thesecond shaft 75 are able to be rotated in different directions.

In the seventh preferred embodiment, the switching mechanism 64 of theceiling suspended shelf 6 includes the coupling belt 141, the first reel142, and the second reel 143. The first reel 142 rotates integrally withthe first shaft 71, and has the coupling belt 141 wound thereon. Thesecond reel 143 rotates integrally with the second shaft 75, and has thecoupling belt 141 wound thereon in the same winding direction as on thefirst reel 142. As the first reel 142 is rotated by the external drivingforce and the coupling belt 141 is wound onto the first reel, the secondreel 143 is rotated in the direction reverse to the rotation directionof the first reel 142. As the second reel 143 is rotated by the externaldriving force and the coupling belt 141 is wound onto the second reel143, the first reel 142 is rotated in the direction reverse to therotation direction of the second reel 143.

Therefore, the belt may not be looped. Accordingly, a short belt is ableto be used to rotate the first shaft and the second shaft in differentdirections.

Thus, the cost of the ceiling suspended shelf 6 is able to be reduced,as compared to a structure including a drive source provided to eachceiling suspended shelf 6.

In the foregoing preferred embodiments, the ceiling suspended shelf 6includes not only the upper shelf 62 but also the lower shelf 65, whichoverlaps the upper shelf 62 in a plan view. The lower shelf 65 islocated lower than the upper shelf 62. The lower shelf 65 does not allowa FOUP 80 to pass therethrough in the up-down direction.

Since the shelves are able to be provided one above the other, the spacein the building is able to be used more effectively.

In the foregoing preferred embodiments, according to the structure ofthe ceiling suspended shelf 6, the number of FOUPs 80 that are able tobe placed in one compartment is smaller in the upper shelf 62 than inthe lower shelf 65.

Accordingly, FOUPs 80 are able to be placed efficiently based on, forexample, a difference in how each FOUP 80 is transported.

In the ceiling suspended shelf 6 of the foregoing preferred embodiments,the FOUP 80 is a wafer transport container to transport wafers. Theupper shelf 62 has, on its upper support surface 62 a, the insertionpins 62 b that are to be received in the recess 81 a formed in thebottom surface 81 of the FOUP 80.

Accordingly, the presence of the insertion pins 62 b in the upper shelf62 is able to stabilize the posture of the FOUP 80.

In the ceiling suspended shelf 6 of the foregoing preferred embodiments,the target position is a position (load port 5) where the FOUP 80 isplaced toward the processing apparatus 4 that is a wafer processor. Theupper shelf 62 is located at a position higher than the target position.

Accordingly, a space located higher than the load port 5 is able to beused effectively.

In the foregoing preferred embodiments, according to the structure ofthe ceiling suspended shelf 6, the upper shelves 62 are provided onopposite sides across the rail 2.

Accordingly, the space in the building is able to be used furthereffectively.

In the foregoing preferred embodiments, the ceiling suspended shelf 6includes the upper side surface guide 63, which faces the side surface83 of the FOUP 80 supported by the upper shelf 62. The upper sidesurface guide 63 is located at a position higher than the lower end ofthe rail 2.

Accordingly, the upper shelf 62 is able to be provided at a relativelyhigh position.

In the preferred embodiments, the ceiling suspended shelf 6 has, on itsback side, the anti-drop structure 67 to prevent the FOUP 80 fromdropping, where the back side is the side opposite to the front sidefacing the rail 2.

Accordingly, dropping of the FOUP 80 is able to be prevented morereliably when, for example, the FOUP 80 is transferred to the ceilingsuspended shelf 6.

While some preferred embodiments of the present invention have beendescribed above, the features and structures described above may bemodified, for example, as follows.

Although in the foregoing preferred embodiments, the ceiling suspendedshelf 6 includes the upper shelf 62 and the lower shelf 65, only theupper shelf 62 may be included. Although in the foregoing preferredembodiments, two FOUPs 80 are able to be placed in one compartment ofthe upper shelf 62 while three FOUPs 80 are able to be placed in onecompartment of the lower shelf 65, the number of FOUPs 80 that are ableto be placed may be changed. The number of FOUPs 80 that are able to beplaced in the upper shelf 62 may be equal to the number of FOUPs 80 thatare able to be placed in the lower shelf 65. Alternatively, the numberof FOUPs 80 that are able to be placed may be larger in the upper shelf62.

In the foregoing preferred embodiments, the upper shelf transfer device40 transfers the FOUP 80 to the upper shelf 62 through the firstmovement involving lateral movement and the second movement involvingupward movement. The FOUP 80, however, may be moved in a different way.For example, the first movement may be preceded by slight downwardmovement to separate the FOUP 80 from the overhead transport vehicle 3.

At least either the chuck 51 or the holding base 52 may hold a sidesurface (including a protruding portion, etc., provided on the sidesurface) of the FOUP 80.

The slide operator 57 of the first preferred embodiment provides adriving force resulting from linear motion to the switching mechanism64, while the rotational operator 59 of the fourth to seventh preferredembodiments provides a driving force resulting from rotational motion tothe switching mechanism 64. In both of these cases, the driving forcesupply is implemented by contacting. Instead, the operator maycontactlessly supply the driving force by, for example, a magnet gear.

Although the foregoing preferred embodiments are described with respectto a non-limiting example of a transport system 1 that is installed in afactory to manufacture semiconductor products, this transport system 1is able to be installed in a factory to manufacture other products, too.This transport system 1 is able to be installed in a building (e.g., awarehouse) other than manufacturing factories.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

1-15. (canceled).
 16. A ceiling suspended shelf where an overheadtransport vehicle temporarily places articles while transporting thearticles to a target position, the overhead transport vehicletransporting the articles by traveling along a rail while beingsuspended, the rail being provided on a ceiling of a building, theceiling suspended shelf being suspended from the ceiling, the ceilingsuspended shelf comprising: an upper shelf including an upper supportsurface that supports the articles; wherein a level of the upper supportsurface is the same or substantially the same as a level of the rail.17. The ceiling suspended shelf according to claim 16, wherein the uppershelf includes a switching mechanism to switch a state of the uppershelf between an open state that allows the articles to pass from belowto above the upper shelf and a closed state that allows the upper shelfto support the articles and does not allow the articles to pass frombelow to above the upper shelf.
 18. The ceiling suspended shelfaccording to claim 17, wherein the switching mechanism is able to switchbetween the open state and the closed state in response to receiving anexternal driving force.
 19. The ceiling suspended shelf according toclaim 18, wherein the upper shelf includes: a first shaft that is ableto rotate; a first support portion to rotate integrally with the firstshaft; a second shaft that is able to rotate, and that has an axialcenter different to an axial center of the first shaft; and a secondsupport portion to rotate integrally with the second shaft, and theswitching mechanism is able to switch between the open state and theclosed state by transmitting to the first shaft an external drivingforce as a rotational force while transmitting to the second shaft anexternal driving force as a rotational force in the direction reverse tothe rotational force transmitted to the first shaft.
 20. The ceilingsuspended shelf according to claim 19, wherein the switching mechanismincludes a coupling link mechanism that couples the first shaft to thesecond shaft, and the coupling link mechanism includes: a first couplinglink that is positioned on a side closest to the first shaft; and asecond coupling link that is positioned on a side closest to the secondshaft, is coupled to the first coupling link, and is rotatable in thedirection reverse to a rotation direction of the first coupling link.21. The ceiling suspended shelf according to claim 19, wherein theswitching mechanism includes: a first shaft link that is rotatableintegrally with the first shaft; a second shaft link that is rotatableintegrally with the second shaft; and a coupling link that couples thefirst shaft link to the second shaft link such that the first shaft linkand the second shaft link are rotatable in different directions.
 22. Theceiling suspended shelf according to claim 19, wherein the switchingmechanism includes: a first pulley; a first belt that is wound aroundthe first pulley to rotate the first shaft; a first gear that isrotatable integrally with the first pulley in the same direction as thefirst pulley; a second gear that is meshed with the first gear directlyor via an even number of gears, to be rotated in the direction reverseto a rotation direction of the first gear; a second pulley that isrotatable integrally with the second gear in the same direction as thesecond gear; and a second belt that is wound around the second pulley torotate the second shaft.
 23. The ceiling suspended shelf according toclaim 19, wherein the switching mechanism includes: a coupling belt; afirst reel that is rotatable integrally with the first shaft, the firstreel including the coupling belt wound thereon; and a second reel thatis rotatable integrally with the second shaft, the second reel includingthe coupling belt wound thereon in the same winding direction as on thefirst reel; as the first reel is rotated by an external driving forceand the coupling belt is wound onto the first reel, the second reel isrotated in the direction reverse to a rotation direction of the firstreel; and as the second reel is rotated by an external driving force andthe coupling belt is wound onto the second reel, the first reel isrotated in the direction reverse to a rotation direction of the secondreel.
 24. The ceiling suspended shelf according to claim 16, furthercomprising: a lower shelf overlapping the upper shelf in a plan view;wherein the lower shelf is lower than the upper shelf; and the lowershelf does not allow the articles to pass therethrough in an up-downdirection.
 25. The ceiling suspended shelf according to claim 24,wherein a number of the articles that are able to be placed in onecompartment is smaller in the upper shelf than in the lower shelf. 26.The ceiling suspended shelf according to claim 16, wherein the articleis a wafer transport container to transport wafers; and the upper shelfincludes, on the upper support surface, an insertion pin that is able tobe received in a recess in a bottom surface of the wafer transportcontainer.
 27. The ceiling suspended shelf according to claim 26,wherein the target position is a position where the wafer transportcontainer is placed toward a processing apparatus to process the wafers;and the upper shelf is located at a position higher than the targetposition.
 28. The ceiling suspended shelf according to claim 16, whereinthe upper shelf includes upper shelves that are provided on oppositesides across the rail.
 29. The ceiling suspended shelf according toclaim 16, further comprising: an upper side surface guide that faces aside surface of the article supported by the upper shelf; wherein theupper side surface guide is located at a position higher than the lowerend of the rail.
 30. The ceiling suspended shelf according to claim 16,wherein the ceiling suspended shelf includes, on a back side of theceiling suspended shelf, an anti-drop structure that prevents thearticles from dropping, and the back side is a side opposite to a frontside facing the rail.